Webinars SET A - Grade 7-8 - Sunday@3:15-4:15pm EST-Recording Webinar 2

Video Transcription

Video Summary

In this webinar session, the instructor covers multiples, factors, divisibility rules, and problem-solving strategies through a series of interactive math problems. Starting with a warm-up on counting multiples of three and excluding numbers ending in three but not divisible by three, the session emphasizes careful analysis in problem solving.<br /><br />Key concepts explained include multiples (products of a number and integers), common multiples, factors (numbers dividing another number without remainder), common factors, and prime numbers, highlighting why 1 is not prime and 2 is the smallest prime number. The instructor details divisibility rules for numbers like 2, 3, 4, 5, 6, 7, 8, 9, and 10 with examples for easy identification.<br /><br />The session then tackles various problems:<br />1. Finding four different positive integers whose product is 100 and determining their sum (answer: 18).<br />2. Identifying the smallest number whose digits multiply to 24 and its digit sum (answer: 11 from 38).<br />3. Calculating when a doorman’s day off coincides again with Sunday considering a 4-day work, 1-day off cycle (answer: 35 days).<br />4. Determining the number of jurors that could produce an average score of 5.625 using fraction conversion (answer: 8 jurors).<br />5. Solving a coin distribution puzzle among pirates with conditional changes in pirates and coin counts, using algebraic reasoning to find total coins (answer: 150 coins).<br />6. Finding digits X and Y in a five-digit number divisible by 4, 5, and 9, using divisibility rules (answer: sum of digits 4).<br />7. Identifying which multiplier yields the most trailing zeros when multiplied by 768, based on factorization focusing on powers of 5 and 2 (answer: option with 5^5 factor).<br /><br />Throughout, participants engage by voting and asking for clarifications. The instructor demonstrates strategies like factorization, use of divisibility tests, and logical deductions essential for solving these numerical puzzles effectively. The session concludes with encouragement for further questions and a warm farewell.

Keywords

multiples

factors

divisibility rules

prime numbers

problem-solving strategies

interactive math problems

factorization

logical deductions

numerical puzzles

math webinar